Hackers have broken into the computer systems of two of the U.S.’ most important science labs, the Oak Ridge National Laboratory (ORNL) in Tennessee and Los Alamos National Laboratory in New Mexico. The hackers accessed a database of visitors for the Oak Ridge Facility that contained the names, social security numbers and dates of births of anyone who visited between 1990 and 2004. The attack was conducted through a flood of phishing emails in October containing malware attachments presumably designed to allow the hackers to bypass security measures.

ORNL director, Thom Mason, described the attacks in an email to staff earlier this week as being a “coordinated attempt to gain access to computer networks at numerous laboratories and other institutions across the country.”

“Because of the sensitive nature of this event, the laboratory will be unable for some period to discuss further details until we better understand the full nature of this attack,” he added.

Not much is known about the Los Alamos attack, but it is assumed the two are linked.